There are number of reasons that you have not received our response for your inquiry.

Although you have sent us many emails in the past few hours. However, we are not operating 24 hours a day. So please be patient until we come back to work after the night and public holiday (refer to our calendar).

If you have not received response from us after many days, please try to check the Trash or Spam folder of your mail box because sometime our emails could be filtered by your mail server (ISP) as Spam.

If you have difficulties in reaching us through email, please try to fax us your questions (remember to leave your fax number for us to respond).

An email with rude content or unreasonable request might be ignored because we are unhappy to argue with the trouble marker.

R/C Helicopter is not undestroyable King Kong so it breaks easily if it hits something or crashing. Please try to keep dropping your mobile phone on the ground to see if that breaks? Would you do that for fun? Of course not because you would expect your mobile would break because of that. So please DO NOT expect the helicopter would be fine no matter how you crash, it is an illogical thought.

Spare parts are consumable, so you need to replace the parts when needed (depends on your skills of course). But Sorry, we do not provide spare parts for free to customers who purchase a helicopter. We would rather to close down our business if we have to, because no one would carry this kind of business. Please be responsible for your fly, the parts would not break without crashing or hitting something by default.

R/C helicopter is not a toy like a 2 years old baby plays. You need skills to master it. In general, it takes at least 3-4 weeks to learn hovering for beginners. Some customers could not even fly after breaking their helicopters. So it is normal. Don't think it is easy to be a real pilot. Please read this article to learn about what does RTF (Ready To Fly) mean?

There is a common mistake by many R/C beginners. They would keep playing the helicopter/plane/car until the battery has no more power to run. But in fact, the battery has been damaged because the voltage of a cell has already gone to the dangerous level. So you should use a Low Voltage Buzzer on RC Hobby to alarm you when the voltage of a cell is below the safe level (~3.5V per cell).

Although battery is a consumable item (can only be used for *N* times) but it would usually last longer if it is not being over-discharged/over-charged. Therefore, please take care your battery, because only you can control its lift time and safety.

If your battery has been damaged due to over-discharged/over-charged, you can google for solutions see if that helps. Otherwise you need to buy a new battery.

** Yes. The battery could be damaged even it was just for first use.
** There is no warranty for this kind of damage since it is not because of product defective. Thank you for your understanding.
** Usually, the voltage of a fully charged battery is 4.2V, you can use it for 6-8 minutes, then it will drop down to about 3.7V. So you must charge the battery before use. Otherwise you will damage the battery.
** In experience, when the voltage of a cell is below 3.8V, some helicopter might not lock the tail well anymore. So you must also recharge.

This question sometimes even raised by experienced R/C Pilots. They always compare the professional gyro (the one being used on their 450 helicopter) with the one on the low cost (especially micro) R/C helicopter (eg. WL V911, NE 260A, etc.). They like to test the performance of Gyro (Tail Holding) of the micro (low cost) helicopter as they always do with a 450 helicopter (or similar size).

This is meaningless because the Gyros on both helicopter are different in class. The Gyro used on 450 helicopter is even expensive than the micro R/C helicopter. Therefore, low cost micro helicopters (these are toy level helicopters only) are not suitable for you if you have a high expectation like you fly with a 450 class helicopter. Thank you for your understanding.

Below are common factors which could cause your Quad / Hex Copter wobbling. The first thing for you to do is to learn and fix it. Sometime it may happen if one ESC or Motor is factory defected but not the case that there is more than one motor or ESC is defective. We build and configure Quad in our warehouse everyday, we have good experience to tell this (avoid to tell us you are the expert because the Quads we build in a week should be more than the Quads any customer builds in his life). The problem is usually from your DIY skill if you have problem on many ESC and Motor.

Propeller

You must make sure you have balanced the propellers properly because most of the wobble caused by propeller (>90%). This is a common mistake that most people forget to balance the propellers.

Please note that propeller will not be balanced by the factory. So you must balance the propeller by yourself.

Buy a new pack of CW and CCW propellers because the propellers you are using might be bent a little.

If you do not know how to balance a propeller, then try to change different combination of props on the Quad to test.

Soldering

If the soldering between ESC and Motor is not good, it would cause wobbling too. So you must make sure you have soldered the cable properly, not just 20-50% of the cable wire.

This is a very common mistake by junior DIY pilots who think they did the work right, but they just miss this part often and blame other people or product mistake and faulty. You should try to re-solder all ESC and Motor again properly.

If you solder the motor cable directly on the ESC Pad, then you must make sure you have removed all wire left by the ESC cable before you solder the motor cable to the ESC.

If the ESC has a problem, it would cause wobbling too but it is not likely to happen.

If you would like to know whether the problem is from the ESC, try to swap ESCs and Motors around to test.

Flight Controller Settings

Sometime, a wobble could be fixed by fine tuning the flight controller. But if you are not an expert of the flight controller, you will have no idea what to do.

You can try to re-calibrate all ESCs using flight controller instead of using Radio Transmitter. So try to re-calibrate all ESCs again (perhaps using another FC)

Motor

Multirotor motor has been balanced by the factory using Motion Balancing Machine so wobble caused by the motor is not likely to happen but usually people will think the motor is causing the problem since they have no idea what to do so they need to find something to blame.

If you think the motor is causing the wobble, you can try to use a smart phone eg. Iphone or Samgsung. There is an apps which can defect the vibration. You mount the motor on a panel or an arm and put the smart phone on it, then use the apps to monitor the vibration with or without propeller. If the motor is the source of wobbling, then you should see that vibration reflects on the apps.

You may also take off all propellers of a Quad, then put the smart phone on the center of the Quad, then monitor the vibration by apps.

Remove the prop mount and test the motor one by one (only one motor at a time), push the throttle up and listen to the motor sound to hear if it is good or not. If you hear strange noise, then there could be a problem in bearing so you need to change the bearing or main shaft.

Sometime the problem could come from the prop mount. If the sound from the motor is nice without prop mount but you hear noise after installing the prop mount, then you might try to change a different prop mount and retry.

There is a soldered part with AWG cable inside the heat sink tubing. If you pull the cables too hard during DIY, then the soldered part of the cable would be loosed and it would cause stuttering (cannot spin at all). You can remove the heat sink tubing to check. If yes, then you can solder it back.

The motor thrust test table is based on the benchmarking result either from the factory or from us. It is always different from your own test result (don't panic now, read on) because the test equipments used for the test are not the same especially the motor thrust stand. No one can claim that the motor thrust stand he is using is 100% accurate and correct (different angle or different length between three pivots could result different thrust).

Also it is incorrect to use a battery (none constant input voltage) to test the motor thrust and compare with the thrust test table only using *amps* because the factory and us usually use constant input voltage from power supply to test the thrust at the fixed voltage input.

We and the factory cannot guarantee the thrust datasheet is 100% correct but at least it should be close to. However, the RPM is accurate because it is usually measured using Hz Calculation or Optical RPM Tachometer which both are pretty accurate. Higher RPM results in Higher Thrust.

Last word, the thrust datasheet is for your reference only, and it does not mean you will have the same thrust because the test we have done so far. Even the same setup with three different ESCs would result different thrust (The ESC controls the Motor). Even same ESC and same Stand but with different firmware version or settings (eg, Timing) flashed on the ESC could also result different thrust.

No complaint / replacement / refund / exchange will be accepted by us for different trust you measured. So please do not purchase a motor from us if you do not agree.

You must check carefully whether the mounting screws are touching the windings (copper wire) inside the motor or not. The mounting screws should not touch the windings otherwise the motor will get overheat and burn the motor and ESC eventually. The screws shipped (AS IS) with the motor could be too long or too short for you depends on the thickness of the panel where you mount the motor so it is out of our control and it is totally your responsible to check before using it. No replacement or refund will be offered for this negligence by customer.

ESC Problem.

Sometime if the ESC is not compatible with the motor, it could cause the motor overheat and finally burn the motor. Especially for the combination of Multirotor ESC and Motor. Some people try to flash a new firmware to the ESC and they do not know not every firmware (even the same firmware but different date) is compatible with the ESC. Some firmwares would cause overheat on both ESC and Motor.

Over Loading.

Your motor is overloading weight. You need to benchmark the motor thrust and compare the flying weight properly.

Each motor has been connected to an ESC and tested manually after assembly in the factory so receiving a motor that does not spin is almost impossible especially if more than one motor does not work.

You need to check the followings in order:

You must check carefully whether the mounting screws are touching the windings (copper wire) inside the motor or not. The mounting screws should not touch the windings otherwise the motor will get overheat and burn the motor and ESC eventually. The screws shipped (AS IS) with the motor could be too long or too short for you depends on the thickness of the panel where you mount the motor so it is out of our control and it is totally your responsible to check before using it. No replacement or refund will be offered for this negligence by customer. Thank you for your kind attention.

Just in case if the motor is completely stuck (you only need to separate the motor bell when the bell is completely stuck). Open the motor and see if there is anything (eg. tiny metal / staple) stuck inside the motor?

If you do not know how to open remove the motor case, please search "change bearing or change motor shaft" on youtube, then you will see lots of videos to show you how.

Because there are magnets inside the motor so any tiny metal could be stuck inside. You may try to use a high power vacuum cleaner to suck the motor, and try to clean up if anything stuck at the magnets.

If your motor is not completely stuck (it means it is just not smooth and sometime may have tick noise because of glue). Connect the ESC and run the motor at full speed (~50% Throttle) for 30-60 seconds (do not mount any propeller).

When a motor is brand new, it sometime happens like this (we assemble many Multirotor copters daily so we have experienced this a lot). Because the factory would put some glue on the motor stator and magnets so you may feel hard to spin it by fingers sometime (the glue on magnets and stator touching each other) but if you spin it for few minutes, then the motor will become smooth again.

The motor, bearings and shaft are all brand new so the motor is completely fine so some people said they have received a motor with bad bearing is also impossible. This issue happens usually just few out of a thousand so it is rare to see. Most people would think the the motor has a bad bearing but the bearings are all brand new so this is almost impossible especially a bad bearing won't cause a motor bell not to spin freely. Instead, the motor with a bad bearing would only cause the motor ​twitching (shaking) during flight.

Each motor has been checked on working condition after assemble by the factory to make sure they at least will spin.

If your motor is jittering and it does not spin together with a "Di Di Di..." sound. It is usually due to the loosed connection on one of the cables between ESC and Motor. If you pull the motor cables too hard during installation or after a crash (motor dropped out and pulled too hard), then the soldered part (usually covered up by the heat sink tubing) of the cable would be loosed and it would cause stuttering (cannot spin at all). You can remove the heat sink tubing to check. If yes, then you can solder it back properly.

A motor would not have any broken copper wire inside if the it works for the first time because you think about it is copper wire so it won't break even you use your hand to pull it hard. The copper wire will break only when it is after a crash.

You may also need to use a another ESC (remember to setup the throttle range first) to test the motor because sometime the problem could be caused by the ESC. Please also try another ESC If you have an ESC of other brand.

Please try to test the motor using a traditional ESC eg. HobbyWing ESC (with traditional HobbyWing firmware). Because some people might have trouble with BLHeli ESC (they do not know how to configure the BLHeli).

This is due to the ESC cannot handle high RPM (all ESCs have this issue depends on the RPM speed you are pushing the motor). This issue appears if you test the Motor and ESC without mounting a propeller at high throttle but it is wrong picture you are seeing because you will be flying with a propeller (not a plain motor).

The larger propeller the slower RPM. So when a propeller is installed on the motor, the RPM of the motor will be much slower so you will not see motor ​twitching again. If you still seeing it ​twitching, then you need to purchase the XRotor or BLHeli ESC (eg. FVT Little Bee with high speed MCU) which you can set the timing to work with the high KV motor (high RPM).

So this is not a problem of the Motor or ESC but combination (Between Motor / Prop / ESC / Battery).

You could smell something similar to "burning smell" during testing when a motor is new (never been used). This is normal because when we test the motor on thrust stand, some motors have this kind of smell too. The smell will be gone after a while. However, not every motor will have this kind of smell.

If the motor is defective (eg. short circuit), the motor would burn itself with spark and you will see the wire inside the motor would turn black (actually you will see it burnt). Otherwise, the just with the smell is totally fine. If you are still worried, we suggest that to return back to us for refund in original condition.

There are advantages and disadvantages to glue the motor shaft into the CNC Motor Case (or bearings). Some factories would use "Loctite 638" on motor shaft and bearing to make sure they will not loose during operation. However, the main disadvantage is that you are difficult to change the motor shaft later because this "Loctite 638" was designed for this purpose and it is a super strong glue.

However, if the motor shaft is unluckily loose from the motor (if you change the motor shaft, the CNC hole will become larger than before too), then it is better for you to apply "Loctite 638" into the hole before you push the shaft back into it.

"Loctite" glue is a famous brand worldwide which you can buy it in your country. Please google if you cannot find it from a nearby hardware store.

2205-2206 size motor can usually generate the trust of about 800-1000g, if you pull the propeller hard by hand, you can normally generate the thrust of 5-10kg. If you cannot pull the motor bell out by hand, that means it is not likely to loose during flight too.

You can get Loctite 332 glue from an authorized dealer of Loctite. We suggest Loctite because it is available worldwide so you can usually get it in your country (please Google).

This glue supports up to 204°C Temperature which is good enough for most flight characteristics. However, an improper combination of Motor, Propeller and Battery could cause motor overheat (hotter than normal) so the magnets of the motor might loose due to failure of glue because of over-driven. We suggest you to either

Change to a smaller propeller (eg. from 6045 to 5045)

Change to a lower cell battery (eg. from 4S to 3S)

Change to a larger motor (eg. from 2205 to 2208)

If your flight characteristics are Extreme 3D, Speedy Racing, Fast Punch-Outs, etc. You should monitor the temperature of the motor after each flight. You need to be careful if the temperature is higher than 100°C. For normal flight, you usually have no such problem.

If the magnets keep loosing out from the motor, that means you should not use the current combination of Motor+Prop+Battery. The propeller, battery and your flight characteristic have over-driven the motor (the motor cannot handle such loading).

There are advantages and disadvantages to use grub screw on a motor. When using grub screw, the CNC shaft hole will be usually larger for people to change the shaft. However, the grub screw may loose during flight so the shaft will then loose out easily. For the motor without grub screw, factory will usually make the hole (shaft housing) smaller so that the shaft will be stuck inside the hole. But after a period of time, the shaft may loose too. So either way the shaft will loose but usually after crash.

Either method, you need to check and maintain the motor just like you do with your car.

Motor is just like a car wheel which maintenance (check-up) is required for safety reason. It makes sense because the Car Dealer won't monitor your usage and condition remotely. For motor with and without Grub Screw, you should check whether both the shaft and grub screw are loose or not. If either is loose, then you should apply some Loctite Glue on it.

For motor without Grub Screw, you can pull the bell hard after installing a propeller, you can easily make a force of over 5KG, if the motor is not loose, then it will be OK for flight because the propeller usually can make a force (thrust) at about 1-2kg at most. So if the bell is not loose when you pull it hard, then it should not be flying off during flight too.

If you apply more Loctite, the shaft/screw will be suck inside so that you are hard to remove it. However, the reverse happens. If you apply less glue, the shaft/screw will loose out easier but it is more easy to remove the shaft/screw. So you can only win one side of a coin and cannot win both sides. We do not have such a magical motor if you are after a motor with no maintenance is required.

USB charge-only cables are not different than traditional USB cables in terms of appearance, they both look same. A faulty data cable may charge but will not establish a data connection between the device and computer.

So you need to make sure the USB cable you are using is Quality Data Charge Cable. If you have a problem with the USB, you try the followings:

Use a different USB Data Cable

Use a different computer with different Operation System (if you have a problem with Win8, then you better try Win7 because Win7 is somehow better than Win8 as we experienced)

Look into the Device Manager section of your computer to see if all hardware devices are working properly. This is important because you have no way to use the device if your computer hardware cannot recognize it.

Further observed, when a data connection is established a Windows based computer may generate a USB connection sound which may not be heard if the cable used is a charge only cable since no data connection is being established.

Since MultiRotor is getting very popular in recent years. Lots of people choose to build the Multirotor Helicopter on their own (DIY) instead of buying a RTF (Ready to Fly) package. Since we also build BNF/RTF Multicopters using the same FC daily so we definitely know whether there is a problem with a batch of FC. If a batch of goods has problem, we will simply return back to the factory to exchange at no cost to us, why do we bother to send you a factory defective product? It does not make sense because we know you will come back to complain.

So the problem comes when people who are stuck during Flight Controller ("FC") configuration if they are not familiar with the FC. These are common ("FC") problems:

During flashing the CC3D firmware (it is in the first stage of setting up the CC3D), the OpenPilot CGS may keep telling you that are unable to communicate with the CC3D so unable to flash the firmware. For this case, you need to retry (re-plug the USB and re-flash the firmware again) until it works (it may need many times of try). Do not ask us why because we do not know. This is very common to CC3D.

Flashing KK 2.1/2.1.5 firmware

You can either use KKMulticopter Flashtool or PROGISP IC Flashing Tool depends on the IC on the KK board. If the IC is ATmega644, then you may need to use PROPGISP because KKMulticopter Flashtool does not support this IC.

Hardware Defection & Driver Issue

It is related to issues of computer hardware and operating system. You should seek assistance from a computer professional if you do not know how to confirm whether you have these problems. This is one of the common problem.

In common case (eg Win 7). There is a Device Manager which you can see a list of hardware devices installed on the motherboard. This should be the first thing you need to check because if the USB is not working properly (eg. no software driver found) then you will normally see an "exclamation mark" next to that hardware.